Acid triphenylmethane dyestuffs and a process of preparing them



Patented Feb. 25, 1936 UNITED STATES PATENT OFFICE ACID TRIPHENYLMETHANE DYESTUFFS AND A PROCESS OF PREPARING THEM Paul Wolfi, Frankfort-on-the-Main-Hochst, Germany, assignor to General Aniline Works, Inc., New York, N. Y., a corporation of Delaware No Drawing. Application September 18, 1933, Serial No. 690,030. In Germany September 29,

8 Claims.

The present invention relates to acid triphenylmethane dyestuffs and to a process of preparing them.

I have found that acid triphenylmethane dyestuffs of very good fastness tolight, clear tint and good color in artificial light are obtainable by a 7 process which comprises condensing a compound of the general formula:

wherein X represents halogen or an alkoxy group, with an indole compound which is substituted in alpha-position by alkyl, aralkyl or aryl, heating the compounds thus obtained of the general formula:

NHzaryl-alkoxy the alkoxy group standing in para-position to the NHz-group, and finally sulfonating the product thus obtained.

The dyestufis thus obtained are new; for instance, dyestufis are obtained which correspond to the following general probable formula:

I Ngalkoxy 020E Ldole (L- 0:

wherein indole represents an indole radical which is bound to the central C-atom in beta-position and which is substituted in alpha-position by alkyl, aralkyl or aryl.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto, the parts being by weight:

(1) 25 parts of 4,4-dichloro-benzophenone are condensed with 2 2 parts of N-methyl-alphaphenylindole in the presence of 20 parts of phosphorus oxychloride by boiling for several hours in 100 parts of toluene. After distillation of the toluene and the phosphorus oxychloride still present the condensation product is melted at 120 C. for 4 hours with 60 parts of paraalkoxy v phenetidine. After cooling, the excess of paraphenetidine is removed from the melt, while stirring, with dilute hydrochloric acid wherein the blue basic dyestuff thus formed is insoluble. After drying, the dyestuff is sulfo-nated with sulfuric acid. There is obtained an acid dyestufi which has the following constitution:

H502 O 0/ 0 0 115 OaNa C\ 0:

C-CoHs dyeing in the form of its sodium salt wool and silk bright blue tints of very good fastness to light and good color in artificial light.

(2) 25 parts of 4,4-dichloro-benzophenone are condensed with 26 parts of N-n-butyl-alphaphenylindole in the presence of 20 parts of phosphorus oxychloride in 100 parts of toluene, as stated in Example 1. The condensation product is melted with para-phenetidine in the same manner as stated in Example 1, and the waterinsoluble blue basic dyestufi thus obtained is isolated and sulfonated with sulfuric acid. There is obtained a blue acid dyestuff which has the following constitution:

| OaNa -S 02 C-CoHs Hr-CHrClir-CH:

(3) 24 parts of 4,4-dimethoxy-benzophenone a are condensed with 24 parts of Bz-2-methyl-N- ethyl-alpha-phenylindole as described in Examples 1 and 2. The condensation product is melted with para-phenetidine inthe same manner as stated in Example 1. The water-insoluble blue dyestuff thus obtained is isolated and sulfonated with sulfuric acid. There is obtained a blue acid dyestuff which has the following constitution:

dyeing in the form of its sodium salt wool and silk bright greenish-blue tints of very good fastness to light and good color in artificial light.

By using instead of 4,4'-dimethoxy-benzophenone another alkoxy compound as, for instance, 4,4-diethoxy-benzophenone, the process may be carried out in the same manner.

(4) 25 parts of 4,4-dichloro-benzophenone are condensed with 24 parts of Bz-3-methy1-N- ethyl-alpha-phenylindole as stated in the preceding examples. The condensation product is melted with 60 parts of para-anisidine. The excess of para-anisidine is removed by means of dilute hydrochloric acid and a basic, Water-insoluble blue dyestufi is obtained. After sulfonating it with sulfuric acid,- there is obtained an acid blue dyestufi which has the following constitution:

Na v I 0:

U O IEhC O- C S OING L dyeing in the form of its sodium salt wool and silk clear blue tints similar to those of the dye stuff described in Example 1 and of the same good properties.

(6) 25 parts of 4,4'-dichloro-benzophenone are condensed with 15 parts of N-methyl-alphamethylindole as stated in the preceding examples. The condensation product is melted at about 120 C. with 60 parts of para-phenetidine'. The excess of phenetidine is removed and a waterinsoluble blue dyestuff is obtained. After sulfonating it and isolating it in the form of its sodium salt there is obtained a dyestufi which dyes wool and silk clear blue tints of a somewhat more red shade than that of the .dyestuff described in Example 1.

By using instead of N-methyl-alpha-methylindole N-methyl-a1pha-benzylindole there is obtained a blue dyestuif having similar properties.

('7) 25 parts of 4,4'dichlorobenzophenone are condensed with 31 parts of N-isobutyl-Bz-2,4- dimethyl-alpha- (parachlorophenyl) -indole in the presence of 20 parts of phosphorus oxychloride by boiling for several hours in parts of toluene. After distillation of the toluene and the phosphorus oxychloride still present, the condensation product is melted at C. for 4 hours with 60 parts of para-phenetidine. After cooling, the

excess of the para-phenetidine is removed from the melt, while stirring, with dilute hydrochloric acid wherein the blue basic dyestuff thus formed is insoluble. After drying, the dyestuif is sulfonated with sulfuric acid. There is obtained an acid dyestuff dyeing in the form of its sodium salt wool and silk bright greenish-blue tints of a very good fastness to light and especially ofa good color in artificial light.

I claim: i

1. The process which comprises condensing a compound of the general formula:

wherein X represents halogen or an alkoxy group, with an indole compound which is substituted in alpha-position by methyl, benzyl or an aryl group of the benzene series, heating the compounds thus obtained of the general formula:

i ndole wherein X has the above meaning and indole represents the alpha-substituted indole radical which is bound to the central C-atom in betaposition, with a primary aromatic amine of the benzene series containing an alkoxy group in para-position to theNHz-group, and finally sulfonating the product thus obtained.

2. The process which comprises boiling for about 2 to about 5 hours in toluene 4,4-dichlorobenzophenone and N-methyl-alpha-phenylindole in the presence of phosphorus oxychloride, melting the condensation product thus obtained of the following formula:

with para-phenetidine for 4 hours at about 120 wherein indole represents an indole radical C. and sulfonating the product thus obtained of which is bound to the central C-atom in betathe following formula: position and which is substituted in alpha-posi- 5 f i v Q O l c H N/ 0 I 6H:

The p ss ch Comprises boiling for tion by methyl, benzyl or an aryl group of the 1 about 2 to about 5 hours in toluene 4.4-dichlorobenzene series, being dyestuifs of a very good dole in the presence of phosphorus oxychloride, artificial light,

melting the condensation product thus obtained 6, The compound of the formula: of the following formula: 1'1 Ill OH I H5020 002115 g OaNa C 0:

-C9H5 C-CaHn N N n-butyl H ph n and N-nbuty p -ph y fastness to light, a clear tint and good color in I with para-phenetidine for 4 hours at about 120 dyeing in the form of its sodium salt wool and C. a d Sulfflnating the product thus Obta ed of silk bright blue tints of very good fastness to the following formula: light and good color in artificial light.

N /LOIHI n-butyl 4. The process which comprises boiling for 7, Th compound of the formula:

about 2 to about 5 hours in toluene 4.4'-dimeth- H H oxy-benzophenone and Bz-2-methyl-N-ethyl- L; alpha-phenylindole in the presence of phosphorus oxychloride, melting the condensation product thus obtained of the following formula: E5020 0% OCIHB 0H OaNa 0:

JJHr-GHz-CHr-CH: dyeing in the form of its sodium salt wool and .1

silk clear blue tints of very good fastness to light I and good color in artificial light. 8. The compound of the formula:

with para-phenetidine for 4 hours at about 120 C. and sulfonating the product thus obtained of H E l I the following formula: N N

H on CQHsOO OTO O H5010 001B 0 C OlNB C\\\ v -C H C-CgH; CH: N/ 0 EC- 6H N 1H The compounds of the formula" dyeing in the form of its sodium salt wool and silk bright greenish-blue tints of a very good alkoxy NomONcffl w fastness to light and a good color in artificial light. 020B mdola (L 0| PAUL WOLFF. 

